[ltp] Battery drain in S3 (was: Question on APM vs ACPI)

[Joachim Schrod]

>>>>> "NK" == Nathan Kurz <nate@verse.com> writes:

NK> On Tue, Dec 07, 2004 at 07:50:59AM +0100, Bob Alexander wrote:
>> From the help I have received from this list and reading around I have 
>> understood that:
>> 
>> 1) APM is much better when suspending in low battery drainage

NK> I've read that many times too, and while I'm certain it was true
NK> at some point for some hardware, I don't know that it is now. I
NK> just did a little measuring on my X30 running 2.6.9 and ACPI S3
NK> suspend-to-ram, and it seems to use abou 550 mW while sleeping. 
NK> This is about 1.25 % of battery capacity per hour, and about what
NK> I've seen people claim for APM sleep.

1.24% per hour == 30% per day

Using APM and a 2.4 kernel, suspend-to-ram (equivalent to S3) eats
roughly 10% battery power per day; both on my T21 and my T41.

Such information (30% battery drain per day in S3) kept me from
migrating to 2.6, for now. (Suspend-to-RAM on lid-close is the most
important function in power management that I need.) OTOH, Fionn
Behrens reported in this thread about a drain of only 5-10% per day.

thinkwiki has no information on battery drain in S3. If you follow up
with more experience, I compile it into information for the
PowerManagement topic there.

Cheers,
	Joachim

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Joachim		     The most exciting phrase to hear in science, the
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